Re: ADD/DROP INHERITS - Mailing list pgsql-hackers

From Greg Stark
Subject Re: ADD/DROP INHERITS
Date
Msg-id 871wtzli7y.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: ADD/DROP INHERITS  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: ADD/DROP INHERITS  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane <tgl@sss.pgh.pa.us> writes:

> Greg Stark <gsstark@mit.edu> writes:
> > Come to think of it it's pretty strange that you can drop an inherited
> > constraint from a child. And doing an experiment it seems you can also DROP
> > NOT NULL on a child which is also pretty strange.
> 
> Yeah.  I think we had agreed that this is a bug.  Note the TODO entries:

Ok, so it's definitely correct for me to require that new children have NOT
NULL if their parent has NOT NULL.

> > I don't see how to block these operations though unless we either search
> > parent classes for constraints to check at run-time or add additional
> > dependency records to block dropping these things.
> 
> The implementation I had in mind was to add columns similar to attinhcount
> and attislocal to pg_constraint.

Hm that would be simpler. That still leaves NOT NULL as a bit of a headache.


-- 
greg



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